From coherent shocklets to giant collective incoherent shock waves in nonlocal turbulent flows

Xu, G., Vocke, D., Faccio, D. , Garnier, J., Roger, T., Trillo, S. and Picozzi, A. (2015) From coherent shocklets to giant collective incoherent shock waves in nonlocal turbulent flows. Nature Communications, 6, 8131. (doi: 10.1038/ncomms9131) (PMID:26348292) (PMCID:PMC4569716)

Abstract

Understanding turbulent flows arising from random dispersive waves that interact strongly through nonlinearities is a challenging issue in physics. Here we report the observation of a characteristic transition: strengthening the nonlocal character of the nonlinear response drives the system from a fully turbulent regime, featuring a sea of coherent small-scale dispersive shock waves (shocklets) towards the unexpected emergence of a giant collective incoherent shock wave. The front of such global incoherent shock carries most of the stochastic fluctuations and is responsible for a peculiar folding of the local spectrum. Nonlinear optics experiments performed in a solution of graphene nano-flakes clearly highlight this remarkable transition. Our observations shed new light on the role of long-range interactions in strongly nonlinear wave systems operating far from thermodynamic equilibrium, which reveals analogies with, for example, gravitational systems, and establishes a new scenario that can be common to many turbulent flows in photonic quantum fluids, hydrodynamics and Bose–Einstein condensates.

• Item Type: Articles
• Additional Information: D.F., D.V. and T.R. acknowledge support from European Research Council under the European Unions Seventh Framework Programme (FP/2007–2013)/ERC GA 306559 and EPSRC (UK, grant EP/J00443X/1). S.T. acknowledges funding from Italian Ministry of Research (grant PRIN 2012BFNWZ2). A.P. and G.X. acknowledge support from the French National Research Agency (ANR-12-BS04-0011 OPTIROC) and the Labex ACTION (ANR-11-LABX-01-01) programme.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Faccio, Professor Daniele
• Authors: Xu, G., Vocke, D., Faccio, D., Garnier, J., Roger, T., Trillo, S., and Picozzi, A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nature Communications
• Publisher: Nature Publishing Group
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2015 Macmillan Publishers Limited
• First Published: First published in Nature Communications 6:8131
• Publisher Policy: Reproduced under a Creative Commons License